Dark Matter and Dark Energy

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Transcript of Dark Matter and Dark Energy

~27% of the UniverseAccounts for gravitational effects that appear to be the result of invisible massThe name is a placeholder for something unknownDiscovered through Gravitation lensingDoesn't emit or absorb light or any other forms of electromagnetic energyControls where ordinary matter piles up to form galaxies and starsnon-baryonic matter(not made of quarks)D A R K M A T T E RG R A V I T I O N A L L E N S I N G D A R K M A T T E R A N DD A R K E N E R G Y In 1932, Jan Ooort observed that stars were moving faster than calculated.Used the term "dark matter" to describe the unidentified mass that caused the difference in the stars velocityThen a year later, Swiss astronomer, Fritz Zwicky used the the speed of galaxy cluster orbits to get the mass of the cluster However, when he compared the mass of clusters to the mass he derived, they are completely differentZwicky independently came to the same same conclusion as OoortH I S T O R Y OF D A R K E N E R G Y D A R K M A T T E R A N DD A R K E N E R G Y D A R K M A T T E R A N DD A R K E N E R G Y

H I S T O R Y O FD A R K M A T T E R D A R K E N E R G Y The diagram above shows the changes in rate of expansion of the universe since its birth 15 billion years ago. Notice the change around 7.5 billion years ago as this is where objects in the universe began moving apart at a faster rate.S O U R C E Shttp://science.howstuffworks.com/dictionary/astronomy-terms/dark-matter.htmhttp://science.nasa.gov/astrophysics/focus-areas/what-is-dark-energy/hubblesite.org/hubble_discoveries/dark_energy/de-what_is_dark_energy.phphttp://www.space.com/20929-dark-energy.htmlhttps://www.ted.com/talks/patricia_burchat_leads_a_search_for_dark_energy?language=enhttp://www.cfhtlens.org/public/what-gravitational-lensinghttp://www.astronomytoday.com/cosmology/darkmatter.htmlhttp://www.smithsonianmag.com/science-nature/dark-energy-the-biggest-mystery-in-the-universe-9482130/?no-isthttp://home.fnal.gov/~skent/early.htmlhttp://science.howstuffworks.com/dictionary/astronomy-terms/big-crunch5.htm

Through thousands of years of studying the sky, astronomers have discovered more than 400 planets orbiting other stars, over 100 billion stars in our own galaxy, and hundreds of billions of galaxies beyond our own. Yet all the baryonic matter in this universe represents a mere 5 percent of what’s actually out there.

So what makes up the rest of the universe ?In theory, dark energy is a kind of dynamical energy fluid or field. Something that fills all space but something whose effect on the expansion of the Universe is the opposite of that of matter and normal energy It was named "quintessence" after the fifth element of the Greek philosophersEven if quintessence was the answer, we don't know why it exists, what it is like or what it interacts with.K E Y S C I E N T I S T S O F D A R K M A T T E RAlbert Einsteinpredicted gravitation lensing in his general theory of relativity

Jan Ooortin 1932 postulated the existence of dark matter to account for the orbital velocities of starts in the Milky Way

Fritz Zwickyin 1933 compared the mass of clusters to the mass he derived and ended up with different results, the difference between the two being dark matterPredicted by Einstein in 1917 as he tried to balance the equations of his general theory of relativity, he called it the cosmological constantHe thought that there must be a force in the universe to spread everything around so evenly and assumed the universe was going to be changelessHowever in 1929, Edwin Hubble showed that the universe was expanding and not static like Einstein thought.Then in 1998 observations made by the Hubble Space Telescope of a very distant supernovae showed that the universe was actually expandingThe expansion of the Universe has been accelerating

I M P L I C A T I O N S O F Edwin HubbleD A R K E N E R G YAlbert EinsteinAn idea of the future of the universe suggests that phantom energy causes divergent expansion. This implies that the effective force of dark energy continues growing until it dominates all other forces in the universe and ultimately tears apart all everything from galaxies and solar systems to atoms themselves. This would end the universe in a "Big Rip."

Another idea of the future is that dark energy would dissolve with time or become attractive. This leads to the possibility of the universe contracting in on itself in a "Big Crunch."

The universe could continue on in its present state forever and never end. While all these ideas are not supported by observations, they're still possibleCould prove one of two theories about the fate of the UniverseThe universe is gonna expand foreverThe universe will collapse in a 'Big Crunch'Ω = the ratio of the actual density of the Universe to its critical densityIf Ω > 1 then gravity will cause the universe to collapse on itselfIf Ω < 1 then the universe will perpetually expandIf Ω = 1 then the universe will expand at a decelerating rate perpetuallyI m p l i c a t i o n s o f D a r k M a t t e rDark energy is theorized to be the force that is expanding the Universe and makes up about 72% of the universeEmpty space is not nothingAccording to cosmological constant, empty space can possess its own energyAs more space comes into existence, so does the energy that fills it. This energy accelerates the expansion of the Universe.The quantum theory of matter explains how space acquires energyEmpty space is filled with temporary or virtual particles that continually form and then disappear.Physicists attempted to calculate how much energy this would give empty space but were off by 10^120Presentation by Julian Luna, Winter Martin, Dennis Tang P.5C O N T I N U E DFritz ZwickyJan OoortQ U I ZW h a t d i d E i n s t e i n b e l i e v e a b o u t t h e u n i v e r s e ?

A)The universe is static B)The universe is expanding C)The universe is condensingD)None of the above